Download What is a Network

Networks, Intranets, Extranets and VPNs
What is a Network?
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an interconnected system of things or people; "he owned a network of shops"; "retirement
meant dropping out of a whole network of people who had been part of my life"
(broadcasting) a communication system consisting of a group of broadcasting stations that
all transmit the same programs; "the networks compete to broadcast important sports
events"
net: an open fabric of string or rope or wire woven together at regular intervals
a system of intersecting lines or channels; "a railroad network"; "a network of canals"
communicate with and within a group; "You have to network if you want to get a good job"
(electronics) a system of interconnected electronic components or circuits
A Computer Network
A connection of 2 or more computers so that they can share information and resources. Common
types are LAN's, WAN's and Intranets
What is an Intranet?
An intranet is a private network that is contained within an enterprise. It may consist of many
interlinked local area networks and also use leased lines in the wide area network. Typically, an
intranet includes connections through one or more gateway computers to the outside Internet. The
main purpose of an intranet is to share company information and computing resources among
employees. An intranet can also be used to facilitate working in groups and for teleconferences.
It is accessible only by the organization's members, employees, or others with authorization. An
intranet's Web site look and act just like any other Web site, but the firewall surrounding an
intranet fends off unauthorized access.
Like the Internet itself, intranets are used to share information. Secure intranets are now the
fastest-growing segment of the Internet because they are much less expensive to build and manage
than private networks based on proprietary protocols.
What is an Extranet?
An extranet is a private network that uses Internet technology and the public telecommunication
system to securely share part of a business's information or operations with suppliers, vendors,
partners, customers, or other businesses. An extranet can be viewed as part of a company's intranet
that is extended to users outside the company. It has also been described as a "state of mind" in
which the Internet is perceived as a way to do business with other companies as well as to sell
products to customers.
An extranet requires security and privacy. These can include firewall server management, the
issuance and use of digital certificates or similar means of user authentication, encryption of
messages, and the use of virtual private networks (VPNs) that tunnel through the public network.
Companies can use an extranet to:
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Exchange large volumes of data using Electronic Data Interchange (EDI)
Share product catalogues exclusively with wholesalers or those "in the trade"
Collaborate with other companies on various projects
Jointly develop and use training programs with other companies
Provide or access services provided by one company to a group of other companies, such as
an online banking application managed by one company on behalf of affiliated banks
Share news of common interest exclusively with partner companies
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What is a Virtual Private Network?
A virtual private network (VPN) is a network that uses a public telecommunication infrastructure,
such as the Internet, to provide remote offices or individual users with secure access to their
organization's network. A virtual private network can be contrasted with an expensive system of
owned or leased lines that can only be used by one organization. The goal of a VPN is to provide the
organization with the same capabilities, but at a much lower cost
VPNs create secure connections or tunnels through the public Internet to transmit data between
individuals, branch offices and a corporate network. Essentially, VPNs employ the Internet for what
has traditionally been handled by either private networking resources or public telephone
networks..
Is a VPN the same as an Extranet?
No, these are entirely different concepts. VPN technology can be used to secure the
communications for an extranet community of buyers and suppliers, but VPNs are also used to
secure many other types of communication – those internal to a company and links between
different companies or agencies for information sharing, for example.
The most common definition of an extranet is a type of network based on Internet technology that
gives outside users, such as business partners, access to data residing on an organization’s private
network. It often enables transactions between a company and its buyers and suppliers. Users can
access data through a Web browser over the Internet and must typically enter a user name and
password to access the data.
A VPN can be used in a similar manner, but provides a much higher level of security at a much more
higher level of access control – from each individual user to each document if necessary.
Specifically, a VPN requires the establishment of a secure pathway into a corporate network while
providing strong encryption, constantly changing session keys, and mutual authentication.
What is a Firewall
A system designed to prevent unauthorized access to or from a private network. Firewalls can be
implemented in both hardware and software, or a combination of both. Firewalls are frequently
used to prevent unauthorized Internet users from accessing private networks connected to the
Internet, especially intranets. All messages entering or leaving the intranet pass through the
firewall, which examines each message and blocks those that do not meet the specified security
criteria.
Computer Security
In the computer industry, refers to techniques for ensuring that data stored in a computer cannot
be read or compromised by any individuals without authorization. Most security measures involve
data encryption and passwords. Data encryption is the translation of data into a form that is
unintelligible without a deciphering mechanism. A password is a secret word or phrase that gives a
user access to a particular program or system.
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